My wifes XC60 R Design brakes felt a bit spongy so i decided to bleed them, they aren't in the best condition (corrosion) but the pads are nearly new. I bled all the brakes but when i got to the last one (front drivers) the bleed nipple snapped. I soaked them all in WD40 before hand and applied some heat to the caliper and they all bled ok except the last. I couldn't get the nipple out with an extractor either and as the calipers were badly corroded i ordered two good corrosion free (relatively) from a 2014 XC60. When they arrived i noticed the replacement calipers are two pot where mine are single piston. The replacement has a bigger footprint and being two pot calipers i thought they'd be an upgrade as they are the same fitment. I stripped them down and cleaned and wire brushed for painting and bought stainless braded hoses and stainless bleed nipples for all 4 calipers. The front right bleed nipple sheared off on the new one despite the lubrication and heat
![Speechless Smiley 004](http://www.volvoforums.org.uk/images/smilies/speechless-smiley-004.gif)
Is it worth trying to get it drilled out and maybe oversized bleed nipples or are the original calipers better anyway? Why did volvo change from two piston to one anyway?